1. Field of the Invention
This invention relates to an image processing system. This invention particularly relates to an image processing system, to which image information input apparatuses and image information output devices are connected. This invention also relates to an improvement in processing of image information in an image processing system. This invention further relates to an image output device.
2. Description of the Prior Art
Various image forming apparatuses (modalities) for diagnosis, in which X-rays, or the like, are utilized, have heretofore been used in the medical field. As such modalities, computed radiography (CR) apparatuses, computed tomography (CT) scanners, magnetic resonance imaging (MRI) apparatuses, and the like, have been used in practice. An image having been formed by each modality is displayed on a cathode ray tube (CRT) display device or is reproduced on film by a laser printer (LP), or the like. The reproduced image is utilized for making a diagnosis, e.g. for investigating the presence or absence of a diseased part or an injury or for ascertaining the characteristics of the diseased part or the injury.
The CR apparatuses are radiation image recording and read-out systems. With the radiation image recording and read-out systems, a radiation image of an object, such as a human body, is recorded on a sheet provided with a layer of a stimulable phosphor (hereinafter referred to as a stimulable phosphor sheet). The stimulable phosphor sheet, on which the radiation image has been stored, is then exposed to stimulating rays, such as a laser beam, which cause it to emit light in proportion to the amount of energy stored thereon during its exposure to the radiation. The light emitted by the stimulable phosphor sheet, upon stimulation thereof, is photoelectrically detected and converted into an electric image signal. Recently the CR apparatuses are widely used in practice. In cases where the CR apparatuses are connected to a network, which will be described later, the CR apparatuses may take on the form of the entire radiation image recording and read-out systems described above or, for example, radiation image read-out apparatuses alone, which can feed the ultimatelly detected image signal (i.e., image information) into the network.
With the rapid advances made in communication technology and computer technology in recent years, various kinds of networks utilizing computers have been built in hospitals. The aforesaid modalities, which were used in the past as stand-alone apparatuses, constitute part of the network as image information input apparatuses. Also, CRT display devices and LP""s constitute part of the network as image information output devices.
The image information input apparatuses (the image forming apparatuses) and the image information output devices have heretofore been produced on the assumption that they will be used alone. Therefore, the problems occurred in that there was no compatibility in the form of image information at the time of input and output of the image information between the image information input apparatuses and the image information output devices. However, with the advances made in the networking technology, the problems are solved little by little.
However, even if the compatibility in the form of image information at the time of input and output of the image information between the image information input apparatuses and the image information output devices is established, and a plurality of kinds of image input modalities and a plurality of image information output devices can be connected as the constituent elements of a network, the problems described below will occur. Specifically, even if the image Information input apparatuses are the ones belonging to the same kind of image input modality, each of the image information input apparatuses will have device characteristics, such as response functions [a contrast transfer function (CTF) and a modulation transfer function (MTF)] and gradation characteristics, which are inherent to the manufacturer and the type or the version (the improvement generation number) of the apparatus. Therefore, in cases where two pieces of image information, which have been inputted from two image information input apparatuses belonging to the same kind of image input modality, are fed into a single image information output device, reproduced images having different image quality are obtained for different manufacturers and different types or versions of the image information input apparatuses.
More specifically, for example, a single image input modality, which is classified as CR apparatuses, includes a CR apparatus made by a manufacturer A and a CR apparatus made by a manufacturer B. As illustrated in FIG. 3A, the CR apparatus of the manufacturer A has a linear profile of gradation characteristics, i.e., the correspondence relationship between input quantity logE (xe2x88x922 to +2), which is obtained from logarithmic transform of radiation dose (0.01 mR to 100 mR), and output quantity represented by digital values of 0 to 1,023. On the other hand, as illustrated in FIG. 3B, the CR apparatus of the manufacturer B has a non-linear profile of gradation characteristics. Therefore, in cases where two pieces of image information, which are fed respectively from the two CR apparatuses, are the ones representing images of the same object, which images have been recorded under the same image recording conditions, and the two pieces of image information are fed into a single CRT display device and respectively reproduced and displayed on the CRT display device, images having identical gradation characteristics cannot be obtained. The difference in gradation characteristics appears as a difference in impression given by the images, and therefore there is a risk that an accurate diagnosis cannot be made.
The same problems also occur with the image information output devices. Specifically, in cases where a single piece of image information is fed into two or more image information output devices having different output device characteristics, visible images having different gradation characteristics, different frequency characteristics, and the like, and giving different impressions are reproduced by the image information output devices.
More specifically, for example, a single kind of image information output device, which is classified as CRT display devices, includes a CRT display device made by a manufacturer A and a CRT display device made by a manufacturer B. The CRT display device of the manufacturer A may have frequency characteristics which are defined by a response function MTFout of a profile shown in FIG. 22A. The CRT display device of the manufacturer B may have frequency characteristics, which are defined by a response function MTFout of a profile shown in FIG. 22B. In such cases, even if a single piece of image information, which has been obtained with a single CR apparatus and represents an image of an object having been recorded under certain image recording conditions, is fed into the two CRT display device, an image reproduced and displayed on the CRT display device of the manufacturer A and an image reproduced and displayed on the CRT display device of the manufacturer B cannot have identical frequency characteristics. The difference in frequency characteristics appears as a difference in impression given by the images, and therefore there is a risk that an accurate diagnosis cannot be made.
The primary object of the present invention is to provide an image processing system, wherein at least two pieces of image information, which are received respectively from at least two image information input apparatuses belonging to a single kind of image input modality, are capable of being processed as pieces of image information, which do not depend upon input device characteristics of the image information input apparatuses.
Besides the cases where act least two image information input apparatuses belong to a single kind of image input modality, the aforesaid problems due to dependence of image information upon image information input apparatuses also occur with respect to image information input apparatuses, which belong to at least two different image input modalities (for example, a CR apparatus and a CT scanner, a CR apparatus and an MRI apparatus, or a CT scanner and an MRI apparatus).
Specifically, for example, a CR apparatus has gradation characteristics such that input quantity logE (xe2x88x922 to +2), which is obtained from logarithmic transform of radiation dose (0.01 mR to 100 mR) and output quantity, which is represented by digital values of 0 to 1,023, may correspond to each other. A CT scanner has gradation characteristics such that input quantity, which is represented by CT values of xe2x88x921,000 to +1,000, and output quantity, which is represented by digital values of 0 to 65,535, may correspond to each other. An MRI apparatus has gradation characteristics such that input quantity, which is represented by a T1 emphasis degree, a T2 emphasis degree, or a hydrogen density, and output quantity, which is represented by digital values of 0 to 65,535, may correspond to each other. Also, ordinarily, the correspondence relationships in the CR apparatus, the CT scanner, and the MRI apparatus are of different profiles.
Therefore, even if the same image processing is carried out on the pieces of image information, which have been obtained from the image information input apparatuses, identical effects of image processing cannot be obtained for the different image information input apparatuses.
Another object of the present invention is to provide an image processing system, wherein at least two pieces of image information, which are received respectively from at least two image information input apparatuses belonging respectively to different kinds of image input modalities, are capable of being processed as pieces of image information, which do not depend upon input device characteristics of the image information input apparatuses.
A further object of the present invention is to provide an image processing system, wherein image processing is carried out such that images, which are reproduced respectively by a plurality of image information output devices that are of the same kind, may not depend upon output device characteristics of the image information output devices.
Besides the cases where at least two image information output devices are of the same kind, the aforesaid problems due to dependence of images, which are reproduced by image information output devices, upon image information output devices also occur with respect to at least two image information output devices, which are of different kinds (for example, an LP and a CRT display device).
A still further object of the present invention is to provide an image processing system, wherein image processing is carried out such that images, which are reproduced respectively by a plurality of image information output devices that are of different kinds, may not depend upon output device characteristics f the image information output devices regardless of the kinds of the image information output devices.
Also, pieces of image information, which are received respectively from a plurality of image information input apparatuses belonging to a single kind of image input modality and having different input device characteristics, may be fed respectively into at least two image information output devices that are of the same kind and that have different output device characteristics, and images may thereby be reproduced by the image information output devices. In such cases, the images, which are reproduced by the image information output devices, depend also upon the input device characteristics of the image information input apparatuses. Therefore, if the output device characteristics of the image information output devices are merely standardized, images having identical image quality cannot be obtained from the image information output devices.
Another object of the present invention is to provide an image processing system, wherein image processing is carried out such that, in cases where pieces of image information, which are received respectively from a plurality of image information input apparatuses belonging to a single kind of image input modality and having different input device characteristics, are reproduced as images respectively by image information output devices that are of the same kind, the reproduced images may not depend upon the input device characteristics and output device characteristics.
Further, in cases where pieces of image information, which are received respectively from different kinds of image input modalities, are reproduced as images by image information output devices that are of different kinds, it is desired that the images reproduced by the image information output devices have identical image quality.
A further object of the present invention is to provide an image processing system, wherein image processing is carried out such that, in cases where pieces of image information, which are received respectively from image information input apparatuses belonging to different kinds of image input modalities, are reproduced as images by image information output devices that are of different kinds, the reproduced images may not depend upon input device characteristics and output device characteristics.
A still further object of the present invention is to provide an image processing system, to which an image information input apparatus and an image information output device are connected, wherein image processing is carried out such that an image, which is reproduced by the image information output device and with a scale of enlargement or a scale of reduction that is desired by the user, may have standard characteristics, which do not depend upon response characteristics of the image information output device and are approximately identical with response characteristics that are obtained in cases where image size enlargement or reduction processing is not carried out.
Another object of the present invention is to provide an image processing system, wherein image processing is carried out such that dependence upon input device characteristics of an image information input apparatus and dependence upon output device characteristics of an image information output device may be canceled.
A further object of the present invention is to provide an improved image information filing method in an image processing system.
A still further object of the present invention is to provide an image output device, wherein an image is capable of being reproduced with output gradation, which is assumed in image processing.
First and second image processing systems in accordance with the present invention are characterized by being provided with a standardization means for transforming image information, which has been received from an image information input apparatus, into standard image information, which does not depend upon device characteristics of the image information input apparatus and depends upon predetermined standard characteristics of the system.
In a first image processing system in accordance with the present invention, image information is unified as standard image information, which depends upon standard characteristics, within a single kind of image input modality. In a second image processing system in accordance with the present invention, image information is unified as standard image information, which depends upon standard characteristics, regardless of the kinds of image input modalities.
Specifically, the present invention provides a first image processing system, to which at least one kind of image input modality and at least one kind of image information output device are connected,
at least one kind of image input modality, which is among connected image input modalities, including a plurality of image information input apparatuses, which have different input device characteristics,
the image processing system comprising:
a standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among the plurality of the image information input apparatuses, the received image information may be transformed into standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously for the image input modality including the one image information input apparatus having fed the image information.
The term xe2x80x9cimage input modalityxe2x80x9d as used herein means one of various kinds of image forming apparatuses for diagnosis, in which X-rays, or the like, are utilized. The kinds of the image input modalities include CR apparatuses, CT scanners, MRI apparatuses, radioisotope (RI) scanners, ultrasonic imaging apparatuses, and the like.
The kinds of the image information output devices include CRT display devices, LP""s, and the like.
The term xe2x80x9cinput device characteristicsxe2x80x9d as used herein means, for example, the characteristics concerning response which are related to frequency characteristics, characteristics concerning gradation that represent the correspondence relationship between, input quantity, which may be represented by radiation dose, or the like, and output quantity, which may be represented by image signal values (image information), or the like.
In the first image processing system in accordance with the present invention, by way of example, the standardization means may comprise:
a) a device characteristics detecting means for detecting the input device characteristics, upon which the received image information depends,
b) an input device characteristics cancel processing means for canceling the dependence of the received image information upon the input device characteristics (the canceling being carried out for each image input modality), and
c) a standardization processing means for transforming the received image information, whose dependence upon the input device characteristics has been canceled, into the standard image information (with respect to each image input modality).
Also, in the first image processing system in accordance with the present invent ion, in order for the input device characteristics to be detected by the device characteristics detecting means, for example, the kind of the modality of the image information input apparatus, which has fed the image information, and elements specifying the input device characteristics may be appended as subsidiary information to the image information. In such cases, the elements specifying the input device characteristics may be profile information or parameter information, which directly defines the input device characteristics. Alternatively, in cases where profile information of each image information input apparatus, or the like, is stored previously in the image processing system, the elements specifying the input device characteristics may be the information specifying the image information input apparatus.
By way of example, the processing of the input device characteristics cancel processing means for canceling the dependence upon the input device characteristics may be carried out with the technique described below.
Specifically, the image information, which is fed from the image information input apparatus into the image processing system, is the one obtained by carrying out transform processing, which depends upon the input device characteristics, on the image information given to the image information input apparatus (the given image information is the raw data, such as radiation dose, before being detected by the image information input apparatus and does not depend upon the input device characteristics). Therefore, inverse transform processing may be carried out such that the image information, which is fed from the image information input apparatus into the image processing system, may be restored into the image information before being detected by the image information input apparatus.
In order for the inverse transform processing to be carried out, each time the input device characteristics are detected by the device characteristics detecting means, a table (an inverse transform table), which defines a profile of the inverse transform, or the like, may be formed in accordance with the detected input device characteristics. Thereafter, the inverse transform processing may be carried out in accordance with the table. Alternatively, the table may be stored previously, and the inverse transform processing may be carried out in accordance with the stored table.
The standard characteristics of the system with respect to each modality may be fixed or may be set such that they can be altered to desired characteristics.
In the first image processing system in accordance with the present invention, predetermined image processing, such as normalization processing [exposure data recognizer (EDR) processing], gradation processing, emphasis processing, image size enlargement or reduction processing (including interpolation processing), or abnormal pattern detection processing, may be carried out on the received image information. In such cases, the predetermined image processing may be carried out on the image information before being processed by the input device characteristics cancel processing means. Alternatively, the predetermined image processing may be carried out on the image information after being processed by the input device characteristics cancel processing means.
The present invention also provides a second image processing system, to which at least two kinds of image input modalities and at least one kind of image information output device are connected,
the image processing system comprising:
a standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from an image information input apparatus belonging to one image input modality, which is among the connected image input modalities, the received image information may be transformed into standard image information, which does not depend upon input device characteristics of the image information input apparatus having fed the image information and depends upon standard device characteristics of the system that have been set previously.
In the second image processing system in accordance with the present invention, as in the first image processing system in accordance with the present invention, the standardization means may comprise:
a) a device characteristics detecting means for detecting the input device characteristics, upon which the received image information depends,
b) an input device characteristics cancel processing means for canceling the dependence of the received image information upon the input device characteristics (the canceling being carried out for each image input modality), and
c) a standardization processing means for transforming the received image information, whose dependence upon the input device characteristics has been canceled, into the standard image information.
Also, in the second image processing system in accordance with the present invention, in order for the input device characteristics to be detected by the device characteristics detecting means, for example, the kind of the modality of the image information input apparatus, which has fed the image information, and elements specifying the input device characteristics may b;appended as subsidiary information to the image information. In such cases, the elements specifying the input device characteristics may be profile information or parameter information, which directly defines the input device characteristics. Alternatively, in cases where profile information of each image information input apparatus, or the like, is stored previously in the image processing system, the elements specifying the input device characteristics may be the information specifying the image information input apparatus.
Further, in the second image processing system in accordance with the present invention, as the standard characteristics of the system, predetermined standard characteristics are employed regardless of the kinds of the image input modalities. The standard characteristics may be fixed or may be set such that they can be altered to desired characteristics.
Third, fourth, fifth, and sixth image processing systems in accordance with the present invention are characterized by being provided with a standardization means for carrying out transform processing on image information, which is to be fed into an image information output device, such that an image which does not depend upon device characteristics of the image information output device and depends upon predetermined standard characteristics of the system, may be reproduced by the image information output device.
In a third image processing system in accordance with the present invention, image information is transformed into image information depending upon standard characteristics, which have been set uniformly within the range of a single kind of image information output device. In a fourth image processing system in accordance with the present invention, image information is transformed into image information depending upon standard characteristics, which have been set uniformly regardless of the kinds of image information output devices. In a fifth image processing system in accordance with the present invention, with respect to image information, which has been received from a single kind of image input modality and is to be fed into a single kind of image information output device, the image information is transformed into image information depending upon standard characteristics, which have been set uniformly within the range of the single kind of image input modality and the single kind of image information output device. In a sixth image processing system in accordance with the present invention, with respect to image information, which has been received from one kind of image input modality and is to be fed into one kind of image information output device, the image information is transformed into image information depending upon standard characteristics, which have been set uniformly regardless of the kinds of image input modalities and the kinds of image information output devices.
Specifically, the present invention further provides a third image processing system, to which at least one kind of image input modality and at least one kind of image information output device are connected,
at least one kind of image information output device, which is among connected image information output devices, including a plurality of image information output devices, which have different output device characteristics,
the image processing system comprising:
a standardization means for carrying out transform processing on image information, which is to be fed into an image information output device, the transform processing being carried out such that, in every case where the image information is to be fed into one image information output device, which is among the plurality of the image information output devices, the image information may be reproduced by the one image information output device to be fed with the image information and as a standard image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously for the kind of the one image information output device to be fed with the image information.
The term xe2x80x9coutput device characteristicsxe2x80x9d as used herein means, for example, input-to-output conversion characteristics of each device, which affect the image quality, such as frequency characteristics, which are represented by response functions (CTF, MTF), and gradation characteristics, which are typically represented by xcex3 values.
The term xe2x80x9cstandard device characteristics having been set previously for a kind of image information output devicexe2x80x9d as used herein means the standard characteristics, which have been set with respect to devices belonging to the kind referred to as CRT display devices, the standard characteristics, which have been set with respect to devices belonging to the kind referred to as LP""s, or the like. The standard characteristics of the CRT display devices and the standard characteristics of the LP""s are set as independent characteristics.
Specifically, for example, in cases where the output device characteristics of a CRT display device and the standard characteristics of the system with respect to the CRT display device are represented respectively by response functions MTF1out and MTF1sys, frequency emphasis processing in accordance with a response correction term xcex1 (=MTF1sys/MTF1out) may be carried out on the image information.
In the third image processing system in accordance with the present invention, by way of example, the standardization means may comprise:
a) an output device characteristics detecting means for detecting the output device characteristics of the one image information output device to be fed with the image information,
b) an output device characteristics cancel processing means for canceling the dependence of the image information, which is reproduced by the one image information output device, upon the output device characteristics of the one image information output device, and
c) a standardization processing means for transforming the image information, whose dependence upon the output device characteristics has been canceled, into image information, which depends upon standard characteristics having been set uniformly for the kind of the one image information output device.
Also, in the third image processing system in accordance with the present invention, in order for the output device characteristics to be detected by the output device characteristics detecting means, for example, elements specifying the output device characteristics may be received from the image information output device, which is to be fed with the image information. In such cases, the elements specifying the output device characteristics may be profile information or parameter information, which directly defines the output device characteristics. Alternatively, in cases where profile information of each image information output device, or the like, is stored previously in the image processing system, the elements specifying the output device characteristics may be the information specifying the image information output device itself.
By way of example, the processing of the output device characteristics cancel processing means for canceling the dependence upon the output device characteristics may be carried out with the technique described below.
Specifically, in accordance with output device characteristics F having been detected by the output device characteristics detecting means, the output device characteristics cancel processing means calculates transform characteristics G such that the output device characteristics F may become inverse transform Gxe2x88x921 of the predetermined transform characteristics G. Thereafter, the output device characteristics cancel processing means carries out transform processing with the transform characteristics G. (As an aid in facilitating the explanation, the transform processing will herein below be referred to as the xe2x80x9cinverse transform processing.xe2x80x9d)
Thereafter, the standardization processing means carries out transform processing on the image information, which has been obtained from the inverse transform processing carried out with the transform characteristics G, and in accordance with predetermined standard characteristics.
The thus obtained image information is the information depending upon the standard characteristics and the transform characteristics G. However, since the image information has been subjected to the transform processing with the output device characteristics F (=Gxe2x88x921) of the image information output device to be fed with the image information, the transform characteristics G of the aforesaid inverse transform processing and the output device characteristics F are canceled each other. Therefore, the image, which is reproduced by the image information output device, does not depend upon the output device characteristics F and depends upon the standard characteristics.
In order for the inverse transform processing to be carried out, each time the output device characteristics F are detected by the output device characteristics detecting means, a table (an inverse transform table), which defines a profile of the inverse transform G, or the like, may be formed in accordance with the detected output device characteristics F. Thereafter, the inverse transform processing may be carried out in accordance with the table. Alternatively, the table may be stored previously, and the inverse transform processing may be carried out in accordance with the stored table.
Also, the transform processing carried out by the standardization means need not necessarily pass through the aforesaid inverse transform processing, and direct transform into the standard characteristics may be carried out.
For example, in cases where the output device characteristics are the modulation transfer function, a difference xcex1 between output device characteristics MTF1out and MTF1sys may be calculated. Also, two-dimensional Fourier transform may be carried out on the image information to be processed, and the image information may thereby be transformed into the frequency domain. Frequency emphasis processing with the aforesaid difference a may then be carried out on the transformed image information. Thereafter, inverse Fourier transform may be carried out.
In lieu of the aforesaid emphasis processing in the frequency domain, emphasis processing in the spatial domain may be carried out by using a spatial-domain filter, such as an unsharp mask filter.
However, with the emphasis processing using the spatial-domain filter, it is substantially impossible to carry out the emphasis in every frequency band. Therefore, for example, in cases where the image information output device is a CRT display device, the visual characteristics of the image information (the image) displayed on the display device may be taken into consideration, and the emphasis may be carried out primarily for a frequency band, which is associated with the highest visual response under ordinary image viewing conditions (e.g., a viewing position spaced 50 cm apart from the displayed image). Therefore, information representing the visual characteristics, viewing characteristics, and the like, may be received from the image information output device. Alternatively, means for storing the information representing such characteristics, or the like, may be provided. However, since there is a difference in visual characteristics between persons who view the images, ordinary visual characteristics may be set as a representative value, or the visual characteristics may be set for each person who views the images.
In cases where the emphasis processing with the unsharp mask filter is employed, the image processing system or the image information output device may be provided with a reference table or a transform table, which represents filter factors that define the unsharp mask filter. Information representing the filter factors obtained from the table may be fed into the standardization processing means, and correction processing may thereby be carried out. Alternatively, the standardization processing means may be provided with the table as part of the constitution.
The standard characteristics of the system with respect to each kind of image information output device may be fixed or may be set such that they can be altered to desired characteristics.
In the third image processing system in accordance with the present invention, predetermined image processing, such as normalization processing [exposure data recognizer (EDR) processing], gradation processing, emphasis processing, image size enlargement or reduction processing (including interpolation processing), or abnormal pattern detection processing, may be carried out on the image information to be fed into the image information output device. In such cases, the predetermined image processing may be carried out on the image information before being processed by the output device characteristics cancel processing means. Alternatively, the predetermined image processing may be carried out on the image information after being processed by the output device characteristics cancel processing means. However, the predetermined image processing should preferably be carried out on the image information before being processed by the output device characteristics cancel processing means. In such cases, setting of image processing conditions can be prevented from becoming complicated.
The present invention still further provides a fourth image processing system, to which at least one kind of image input modality and at least two kinds of image information output devices are connected,
the image processing system comprising:
a standardization means for carrying out transform processing on image information, which is to be fed into an image information output device, the transform processing being carried out such that, in every case where the image information is to be fed into one image information output device, which is among the plurality of the image information output devices, the image information may be reproduced by the one image information output device to be fed with the image information and as a standard image, which does not depend upon output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics of the system that have been set previously.
In the fourth image processing system in accordance with the present invention, by way of example, the standardization means may comprise:
a) an output device characteristics detecting means for detecting the output device characteristics of the one image information output device to be fed with the image information,
b) an output device characteristics cancel processing means for canceling the dependence of the image information, which is reproduced by the one image information output device, upon the output device characteristics of the one image information output device, and
c) a standardization processing means for transforming the image information, whose dependence upon the output device characteristics has been canceled, into image information, which depends upon standard characteristics of the system that have been set previously and uniformly regardless of the kinds of the image information output devices.
The present invention also provides a fifth image processing system, to which at least one kind of image input modality and at least one kind of image information output device are connected,
at least one kind of image input modality, which is among connected image input modalities, including a plurality of image information input apparatuses, which have different input device characteristics,
at least one kind of image information output device, which is among connected image information output devices, including a plurality of image information output devices, which have different output device characteristics,
the image processing system comprising:
a standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among the plurality of the image information input apparatuses, and the image information is to be fed into one image information output device, which is among the plurality of the image information output devices, the image information may be reproduced by the one image information output device to be fed with the image information and as a standard image, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously for the kind of the image input modality including the one image information input apparatus having fed the image information and for the kind of the one image information output device to be fed with the image information.
The term xe2x80x9cinput device characteristicsxe2x80x9d as used herein for the fifth image processing system in accordance with the present invention has the same meaning as that described above.
In the fifth image processing system in accordance with the present invention, by way of example, the standardization means may comprise:
a) a device characteristics detecting means for detecting the input device characteristics of the one image information input apparatus having fed the image information and the output device characteristics of the one image information output device to be fed with the image information,
b) a device characteristics cancel processing means for canceling the dependence of the image information, which has been received from the one image information input apparatus and is reproduced by the one image information output device, upon the input device characteristics of the one image information input apparatus and the output device characteristics of the one image information output device, and
c) a standardization processing means for transforming the image information, whose dependence upon the input device characteristics and the output device characteristics has been canceled, into image information, which depends upon standard characteristics having been set uniformly for the combination of the kind of the image input modality including the one image information input apparatus and the kind of the one image information output device.
Also, in the fifth image processing system in accordance with the present invention, in order for the input device characteristics to be detected by the device characteristics detecting means, for example, the aforesaid technique for detecting the input device characteristics, which is employed in the device characteristics detecting means in the first image processing system in accordance with the present invention, may be employed. In order for the output device characteristics to be detected by the device characteristics detecting means, for example, the aforesaid technique for detecting the output device characteristics, which is employed in the output device characteristics detecting means in the third image processing system in accordance with the present invention, may be employed.
As the processing of the device characteristics cancel processing means for canceling the dependence upon the input device characteristics, the aforesaid processing for canceling the dependence upon the input device characteristics, which is employed in the input device characteristics cancel processing means in the first image processing system in accordance with the present invention, may be employed.
The standard characteristics of the system with respect to each kind of modality may be fixed or may be set such that they can be altered to desired characteristics.
As the processing of the device characteristics cancel processing means for canceling the dependence upon the output device characteristics, the aforesaid processing for canceling the dependence upon the output device characteristics, which is employed in the output device characteristics cancel processing means in the third image processing system in accordance with the present invention, may be employed.
In the manner described above, with the device characteristics cancel processing means, the processing for canceling the dependence upon the input device characteristics and the processing for canceling the dependence upon the output device characteristics may be carried out separately. Alternatively, characteristics (hereinbelow referred to as the input-output device characteristics), which are obtained by combining the input device characteristics and the output device characteristics with each other, may be calculated, and processing for canceling the dependence upon the input-output device characteristics may be carried out.
The present invention further provides a sixth image processing system, to which at least two kinds of image input modalities and at least two kinds of image information output devices are connected,
the image processing system comprising:
a standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from an image information input apparatus belonging to one image input modality, which is among the connected image input modalities, and the image information is to be fed into one image information output device, which is among the plurality of the image information output devices, the image information may be reproduced by the one image information output device to be fed with the image information and as a standard image, which does not depend upon input device characteristics of the image information input apparatus having fed the image information and output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics that have been set previously.
In the sixth image processing system in accordance with the present invention, by way of example, the standardization means may comprise:
a) a device characteristics detecting means for detecting the input-device characteristics of the image information input apparatus having fed the image information and the output device characteristics of the one image information output device to be fed with the image information,
b) a device characteristics cancel processing means for canceling the dependence of the image information, which has been received from the image information input apparatus and is reproduced by the one image information output device, upon the input device characteristics of the image information input apparatus and the output device characteristics of the one image information output device, and
c) a standardization processing means for transforming the image information, whose dependence upon the input device characteristics and the output device characteristics has been canceled, into image information, which depends upon standard characteristics of the system that have been set previously.
Seventh, eighth, and ninth image processing systems in accordance with the present invention are characterized by carrying out frequency emphasis processing (including smoothing processing) on image information, or correcting the processing parameters (including those with filter factors, and the like) for transform processing carried out by a standardization means on the image information, or correcting the parameters (including those with filter factors, and the like) for interpolation processing accompanying image size enlargement or reduction processing carried out on the image information, such that variation in response characteristics due to image size enlargement or reduction processing may be compensated for.
Specifically, the present invention still further provides a seventh image processing system, to which at least one kind of image information input apparatus and at least one kind of image information output device are connected,
the image processing system comprising:
i) a standardization means for carrying out transform processing on image information and in accordance with response characteristics of one image information output device, into which the image information is to be fed, such that the image information may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the response characteristics of the one image information output device to be fed with the image information and depends upon standard response characteristics having been set previously,
ii) a response characteristics variation calculating means for calculating a variation component of the image from the standard response characteristics in cases where the image reproduced by the one image information output device is subjected to image size enlargement processing with a desired scale of enlargement or image size reduction processing with a desired scale of reduction, and
iii) a correction means for carrying out frequency emphasis processing on the image information such that the variation component may be compensated for.
The kinds of the image information input apparatuses include CR apparatuses, CT scanners, MRI apparatuses, radioisotope (RI) scanners, ultrasonic imaging apparatuses and the like.
The kinds of the image information output devices include CRT display devices, LP""s, and the like.
The term xe2x80x9cresponse characteristicsxe2x80x9d as used herein means the frequency response characteristics represented by response functions (CTF, MTF).
An image size enlargement or reduction processing means, which carries out the image size enlargement or reduction processing with a desired scale of enlargement or a desired scale of reduction, may be provided in the seventh image processing system (or each of the eighth and ninth image processing systems) in accordance with the present invention or in the image information output device. In cases where the image information output device is provided with the image size enlargement or reduction processing means, an image size enlargement or reduction processing information input means should preferably be provided such that the response characteristics variation calculating means can receive information, which defines the details of the image size enlargement or reduction processing carried out by the image size enlargement or reduction processing means, from the image information output device. In such cases, as the information, which defines the details of the image size enlargement or reduction processing, for example, parameters (including filter factors, and the like), which define the details of interpolation processing constituting the image size enlargement or reduction processing, may be employed. The details of the interpolation processing include the type of the interpolating operation (a first-order interpolating operation, a second-order Lagrangean interpolating operation, a third-order B spline interpolating operation, a third-order cubic spline interpolating operation, or the like), filter factors in the interpolating operation, and the like.
The term xe2x80x9cstandard response characteristics having been set previouslyxe2x80x9d as used herein means the response characteristics having been set as a standard, instead of the response characteristics of the image information output device to be fed with the image information, such as a CRT display device.
Specifically, for example, in cases where the response characteristics of the image information output device to be fed with the image information and the standard characteristics are represented respectively by response functions MTFout and MTF1sys, frequency emphasis processing in accordance with a response correction term xcex1 (=MTF1sys/MTF1out) may be carried out on the image information.
In the seventh image processing system (or each of the eighth and ninth image processing systems) in accordance with the present invention, by way of example, the standardization means may comprise:
a) a response characteristics detecting means for detecting the response characteristics of the one image information output device to be fed with the image information,
b) a response characteristics cancel processing means for canceling the dependence of the image information, which is reproduced by the one image information output device, upon the response characteristics of the one image information output device, and
c) a standardization processing means for transforming the image information, whose dependence upon the response characteristics has been canceled, into image information, which depends upon standard characteristics having been set uniformly for the kind of the one image information output device or for all kinds of image information output devices.
Also, in order for the response characteristics to be detected by the response characteristics detecting means, for example, elements specifying the response characteristics may be received from the image information output device, which is to be fed with the image information. In such cases, the elements specifying the response characteristics may be profile information or parameter information (the filter factors, or the like), which directly defines the response characteristics. Alternatively, in cases where profile information of each image information output device, or the like, is stored previously in the image processing system, the elements specifying the response characteristics may be the information specifying the image information output device itself.
By way of example, the processing of the response characteristics cancel processing means for canceling the dependence upon the response characteristics may be carried out with the technique described below.
Specifically, in accordance with response characteristics F having been detected by the response characteristics detecting means, the response characteristics cancel processing means calculates transform characteristics G such that the response characteristics F may become inverse transform Gxe2x88x921 of the predetermined transform characteristics G. Thereafter, the response characteristics cancel processing means carries out transform processing with the transform characteristics G. (As an aid in facilitating the explanation, the transform processing will hereinbelow be referred to as the xe2x80x9cinverse transform processing.xe2x80x9d)
Thereafter, the standardization processing means carries out transform processing on the image information, which has been obtained from the inverse transform processing carried out with the transform characteristics G, and in accordance with predetermined standard characteristics.
The thus obtained image information is the information depending upon the standard characteristics and the transform characteristics G. However, since the image information has been subjected to the transform processing with the response characteristics F (=Gxe2x88x921) of the image information output device to be fed with the image information, the transform characteristics G of the aforesaid inverse transform processing and the response characteristics F are canceled each other. Therefore, the image, which is reproduced by the image information output device, does not depend upon the response characteristics F and depends upon the standard characteristics.
In order for the inverse transform processing to be carried out, each time the response characteristics F are detected by the response characteristics detecting means, a table (an inverse transform table), which defines a profile of the inverse transform G, or the like, may be formed in accordance with the detected response characteristics F. Thereafter, the inverse transform processing may be carried out in accordance with the table. Alternatively, the table may be stored previously, and the inverse transform processing may be carried out in accordance with the stored table.
Also, the transform processing carried out by the standardization means need not necessarily pass through the aforesaid inverse transform processing, and direct transform into the standard characteristics may be carried out. Specifically, a difference a between response characteristics MTF1out and MTF1sys may be calculated. Also, two-dimensional Fourier transform may be carried out on the image information to be processed, and the image information may thereby be transformed into the frequency domain. Frequency emphasis processing with the aforesaid difference a may then be carried out on the transformed image information. Thereafter, inverse Fourier transform may be carried out.
In lieu of the aforesaid emphasis processing in the frequency domain, emphasis processing (or smoothing processing) in the spatial domain may be carried out by using a spatial-domain filter, such as an unsharp mask filter.
However, with the emphasis processing using the spatial-domain filter, it is substantially impossible to carry out the correction (i.e., the emphasis or the smoothing) in every frequency band. Therefore, for example, in cases where the image information output device is a CRT display device, the visual characteristics of the image information (the image) displayed on the display device may be taken into consideration, and the correction may be carried out primarily for a frequency band, which is associated with the highest visual response under ordinary image viewing conditions (e.g., a viewing position spaced 50 cm apart from the displayed image). Therefore, information representing the visual characteristics, viewing characteristics, and the like, may be received from the image information output device. Alternatively, means for storing the information representing such characteristics, or the like, may be provided. However, since there is a difference in visual characteristics between persons who view the images, ordinary visual characteristics may be set as a representative value, or the visual characteristics may be set for each person who views the images.
In cases where the correction processing with the unsharp mask filter is employed, the image processing system or the image information output device may be provided with a reference table or a transform table, which represents filter factors that define the unsharp mask filter. Information representing the filter factors obtained from the table may be fed into the standardization processing means, and correction processing may thereby be carried out. Alternatively, the standardization processing means may be provided with the table as part of the constitution.
The standard characteristics described above may be fixed or may be set such that they can be altered to desired characteristics.
In the seventh image processing system in accordance with the present invention, as the techniques for the frequency emphasis processing carried out by the correction means, one of various techniques may be employed. Specifically, it is possible to employ the aforesaid technique utilized for the standardization in the standardization means, which technique comprises carrying out Fourier transform on the image information, making a correction in the frequency domain such that the aforesaid difference may be eliminated, and thereafter carrying out inverse Fourier transform into the image region. Alternatively, frequency processing, in which a spatial-domain filter, such as an unsharp mask filter, is utilized, may be employed (such frequency processing is described in, for example, U.S. Pat. No. 4,315,318).
In the aforesaid seventh image processing system in accordance with the present invention, the correction means directly carries out the frequency emphasis processing on the image information. Alternatively, as in the eighth image processing system in accordance with the present invention, a correction means may correct the processing parameters (including those with filter factors, and the like) for transform processing carried out by the standardization means.
Specifically, the present invention also provides an eighth image processing system, to which at least one kind of image information input apparatus and at least one kind of image information output device are connected,
the image processing system comprising:
i) a standardization means for carrying out transform processing on image information and in accordance with response characteristics of one image information output device, into which the image information is to be fed, such that the image information may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the response characteristics of the one image information output device to be fed with the image information and depends upon standard response characteristics having been set previously,
ii) a response characteristics variation calculating means for calculating a variation component of the image from the standard response characteristics in cases where the image reproduced by the one image information output device is subjected to image size enlargement processing with a desired scale of enlargement or image size reduction processing with a desired scale of reduction, and
iii) a correction means for correcting parameters, which define details of the transform processing carried out by the standardization means, such that the variation component may be compensated for.
As described above for the seventh image processing system in accordance with the present invention, in cases where the standardization means utilizes the Fourier transform and the inverse Fourier transform, the parameters, which define the details of the transform processing carried out by the standardization means, may be the profile information, which defines the aforesaid transform characteristics G, or the like. In cases where the standardization means utilizes the spatial-domain filter, the parameters, which define the details of the transform processing carried out by the standardization means, may be the filter factors, which define the unsharp mask filter, or the like.
As another alternative, as in the ninth image processing system in accordance with the present invention, a correction means may correct the parameters (including those with filter factors, and the like) for interpolation processing, which define details of the interpolation processing accompanying the image size enlargement or reduction processing.
Specifically, the present invention further provides a ninth image processing system, to which at least one kind of image information input apparatus and at least one kind of image information output device are connected,
the image processing system comprising:
i) a standardization means for carrying out transform processing on image information and in accordance with response characteristics of one image information output device, into which the image information is to be fed, such that the image information may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the response characteristics of the one image information output device to be fed with the image information and depends upon standard response characteristics having been set previously,
ii) a response characteristics variation calculating means for calculating a variation component of the image from the standard response characteristics in cases where the image reproduced by the one image information output device is subjected to image size enlargement processing with a desired scale of enlargement or image size reduction processing with a desired scale of reduction, and
iii) a correction means for correcting parameters, which define details of interpolation processing accompanying the image size enlargement processing or accompanying the image size reduction processing, such that the variation component may be compensated for.
The parameters, which define the details of the interpolation processing accompanying the image size enlargement processing or accompanying the image size reduction processing, may be ones representing the type of the interpolating operation (a first-order interpolating operation, a second-order Lagrangean interpolating operation, a third-order B spline interpolating operation, a third-order cubic spline interpolating operation, a spline interpolating operation which enables adjustment of sharpness, or the like), filter factors for the interpolating operation, and the like.
The interpolation processing should preferably be carried out with an interpolating operation technique (i.e., a spline interpolating operation technique enabling adjustment of sharpness), which combines an interpolating operation process that yields a comparative high level of sharpness, such as athird-order cubic spline interpolating operation, and an interpolating operation process that yields a comparative low level of sharpness, such as a third-order B spline interpolating operation. The spline interpolating operation technique enabling adjustment of sharpness is described in, for example, U.S. patent application Ser. No. 08/679,8,30.
The spline interpolating operation technique enabling adjustment of sharpness comprises the steps of:
i) obtaining an original image signal (image information), which represents an original image and is made up of a series of original image signal components Yij,
ii) linearly combining interpolation coefficients Bij and Cij, which correspond to each other and are set for each of the original image signal components Yij, in two different interpolating functions f and g for obtaining two interpolation images having different levels of sharpness, which functions are represented by Formulas (1) and (2), the linear combination being carried out with Formula (3), a new interpolation coefficient Aij being obtained from the linear combination, and
iii) carrying out an interpolating operation on the original image signal components Yij by using an interpolating function h having the new interpolation coefficient Aij, which function is represented by Formula (4).
f=xcexa3Bijxc2x7Yijxe2x80x83xe2x80x83(1)
g=xcexa3Cijxc2x7Yijxe2x80x83xe2x80x83(2)
Aij=(1xe2x88x92xcex1)Bij+xcex1Cijxe2x80x83xe2x80x83(3)
h=xcexa3Aijxc2x7Yijxe2x80x83xe2x80x83(4)
in which i=1, 2, . . . , and j=1, 2, . . . .
The coefficient a in Formula (3) is set to be one of all real numbers including a range smaller than 0 and/or a range larger than 1. The correction means may correct the coefficient a, which is the weight factor for the weighting of the interpolation coefficients Bij and Cij. As the two different interpolating functions f and g, the third-order cubic spline interpolating operation function and the third-order B spline interpolating operation function de scribed above should preferably be employed.
In tenth, eleventh, twelfth, and thirteenth image processing systems in accordance with the present invention, with respect to image information having been received from an image information input apparatus, processing for canceling the dependence upon input device characteristics of the image information input apparatus, normalization processing, image processing, and processing for canceling the dependence upon output device characteristics of an image information output device, into which the image information is to be fed, are carried out. Each of the tenth, eleventh, twelfth, and thirteenth image processing systems in accordance with the present invention is characterized by being provided with a filing means for appending profile information for each processing to the image information in a step prior to one of the aforesaid processings, the profile information being necessary for each of the subsequent processings.
In a tenth image processing system in accordance with the present invention, the filing is carried out in a step prior to the processing for canceling the dependence upon input device characteristics. In an eleventh image processing system in accordance with the present invention, the filing is carried out in a step prior to the normalization processing. In a twelfth image processing system in accordance with the present invention, the filing is carried out in a step prior to the image processing. In a thirteenth image processing system in accordance with the present invention, the filing is carried out in a step prior to the processing for canceling the dependence upon output device characteristics.
Specifically, the present invention still further provides a tenth image processing system, to which at least one image information input apparatus (e.g., a CR apparatus, a CT scanner, an MRI apparatus, an RI scanners, an ultrasonic imaging apparatus) having inherent input device characteristics and at least one image information output device (e.g., a CRT display device or an LP) having inherent output device characteristics are connected,
the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means,
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously, and
v) a filing means for appending pieces of profile information to the image information, which is fed into the input standardization means, the pieces of profile information comprising first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means, second profile information, which is necessary for defining details of the image processing carried out by the image processing means, third profile information, which is necessary for defining details of the normalization processing carried out by the normalization processing means, and fourth profile information, which is necessary for defining details of the transform processing carried out by the input standardization means.
The term xe2x80x9cinput device characteristicsxe2x80x9d as used herein for the tenth image processing system (and the eleventh, twelfth, and thirteenth image processing systems) in accordance with the present invention has the same meaning as that described above.
The term xe2x80x9coutput device characteristicsxe2x80x9d as used herein for the tenth image processing system (and the eleventh, twelfth, and thirteenth image processing systems) means, for example, the characteristics concerning response which are related to frequency characteristics, the characteristics concerning gradation that represent the correspondence relationship between input quantity, which may be represented by image signal values (image information), or the like, and output quantity, which may be represented by luminance, image density, or the like.
By way of example, the input standardization means may comprise:
a) an input device characteristics detecting means for detecting the input device characteristics, upon which the received image information depends,
b) an input device characteristics cancel processing means for canceling the dependence of the received image information upon the input device characteristics (the canceling being carried out for each image input modality, i.e., for each kind of the image information input apparatus), and
c) an input standardization processing means for transforming the received image information, whose dependence upon the input device characteristics has been canceled, into the standard image information (with respect to each image input modality).
Also, in order for the input device characteristics to be detected by the input device characteristics detecting means, for example, the kind of the modality of the image information input apparatus, which has fed the image information, and elements specifying the input device characteristics may be appended as subsidiary information to the image information. Alternatively, the information representing the kind of the modality of the image information input apparatus, which feeds the image information, and elements specifying the input device characteristics may be stored in a memory, or the like, of the input standardization means, and the input device characteristics detecting means may read the stored information. In such cases, the elements specifying the input device characteristics may be profile information or parameter information, which directly defines the input device characteristics. Alternatively, in cases where profile information of each image information input apparatus, or the like, is stored previously in the input standardization means, the elements specifying the input device characteristics may be the information specifying the image information input apparatus which feeds the image information.
As the processing of the input device characteristics cancel processing means for canceling the dependence upon the input device characteristics, the aforesaid processing for canceling the dependence upon the input device characteristics, which is employed in the input device characteristics cancel processing means in the first image processing system in accordance with the present invention, may be employed.
The standard characteristics of the system with respect to each modality may be fixed or may be set such that they can be altered to desired characteristics.
The normalization processing is the processing, which is carried out with respect to the image information having been received from the image information input apparatus (in particular, a CR apparatus) in order to adjust image processing conditions for appropriately processing an object image portion of interest in the image information. With the normalization processing, the object image portion is extracted appropriately. Such normalization processing is described in, for example, U.S. Pat. No. 5,272,339.
As the image processing, frequency emphasis processing (including smoothing processing), gradation processing, image size enlargement or reduction processing (including interpolation processing), abnormal pattern detection processing, or the like, may be employed.
By way of example, the output standardization means may comprise:
a) an output device characteristics detecting means for detecting the output device characteristics of the one image information output device to be fed with the image information,
b) an output device characteristics cancel processing means for canceling the dependence of the image information, which is reproduced by the one image information output device, upon the output device characteristics of the one image information output device, and
c) an output standardization processing means for transforming the image information, whose dependence upon the output device characteristics has been canceled, into image information, which depends upon standard characteristics having been set uniformly for the kind of the one image information output device.
Also, in order for the output device characteristics to be detected by the output device characteristics detecting means, for example, elements specifying the output device characteristics may be received from the image information output device, which is to be fed with the image information. Alternatively, the elements specifying the output device characteristics may be stored in a memory, or the like, of the output standardization means, and the output device characteristics detecting means may read the stored information. In such cases, the elements specifying the output device characteristics may be profile information or parameter information, which directly defines the output device characteristics. Alternatively, in cases where profile information of each image information output device, or the like, is stored previously in the output standardization means, the elements specifying the output device characteristics may be the information specifying the image information output device itself.
By way of example, the processing of the output device characteristics cancel processing means for canceling the dependence upon the output device characteristics may be carried out with the technique described below.
Specifically, in accordance with output device characteristics F having been detected by the output device characteristics detecting means, the output device characteristics cancel processing means calculates transform characteristics G such that the output device characteristics F may become inverse transform Gxe2x88x921 of the predetermined transform characteristics G. Thereafter, the output device characteristics cancel processing means carries out transform processing with the transform characteristics G. (As an aid in facilitating the explanation, the transform processing will hereinbelow be referred to as the xe2x80x9cinverse transform processing.xe2x80x9d)
Thereafter, the output standardization processing means carries out transform processing on the image information, which has been obtained from the inverse transform processing carried out with the transform characteristics G, and in accordance with predetermined standard characteristics.
The thus obtained image information is the information depending upon the standard characteristics and the transform characteristics G. However, since the image information has been subjected to the transform processing with the output device characteristics F (=Gxe2x88x921) of the image information output device to be fed with the image information, the transform characteristics G of the aforesaid inverse transform processing and the output device characteristics F are canceled each other. Therefore, the image, which is reproduced by the image information output device, does not depend upon the output device characteristics F and depends upon the standard characteristics.
In order for the inverse transform processing to be carried out, each time the output device characteristics F are detected by the output device characteristics detecting means, a table (an inverse transform table), which defines a profile of the inverse transform G, or the like, may be formed in accordance with the detected output device characteristics F. Thereafter, the inverse transform processing may be carried out in accordance with the table. Alternatively, the table may be stored previously, and the inverse transform processing may be carried out in accordance with the stored table.
Also, the transform processing carried out by the output standardization means need not necessarily pass through the aforesaid inverse transform processing, and direct transform into the standard characteristics may be carried out.
The standard characteristics of the system with respect to each image information output device may be fixed or may be set such that they can be altered to desired characteristics.
The first profile information may be, for example, the information representing the output device characteristics of the image information output device, into which the image information is to be fed, or parameters, which define the output device characteristics. The first profile information may be other information, which enables the output standardization means to determine the details of the transform processing to be carried out on the image information.
The second profile information may be, for example, the information representing the gradation, the resolution, or the image size, which the visible image should have. The second profile information may be other information, which enables the image processing means to determine the details of the image processing to be carried out on the image information.
The third profile information may be, for example, index values (e.g., parameters corresponding to the read-out sensitivity and the latitude), which determine the range of the image information to be extracted. The third profile information may be other information, which enables the normalization processing means to determine the details of the normalization processing to be carried out on the image information.
The fourth profile information may be, for example, the information representing the input device characteristics of the image information input device, which feeds the image information, or parameters, which define the input device characteristics. The fourth profile information may be other information, which enables the input standardization means to determine the details of the standardization processing to be carried out on the image information.
The present invention also provides an eleventh image processing system, to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected,
the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into input standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the input standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means,
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously, and
v) a filing means for appending pieces of profile information to the input standard image information, the pieces of profile information comprising first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means, second profile information, which is necessary for defining details of the image processing carried out by the image processing means, and third profile information, which is necessary for defining details of the normalization processing carried out by the normalization processing means.
The present invention further provides a twelfth image processing system, to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected,
the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into input standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the input standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means,
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously, and
v) a filing means for appending pieces of profile information to the image information, which has been normalized, the pieces of profile information comprising first pro file information, which is necessary for defining details of the transform processing carried out by the output standardization means, and second profile information, which is necessary for defining details of the image processing carried out by the image processing means.
The present invention still further provides a thirteenth image processing system, to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected,
the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into input standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the input standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means,
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously, and
v) a filing means for appending profile information to the image information, which has been obtained from the image processing, the profile information being first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means.
Further, the present invention provides image information filing methods for use in an image processing system wherein, with respect to image information having been received from an image information input apparatus, processing for canceling the dependence upon input device characteristics of the image information input apparatus, normalization processing, image processing, and processing for canceling the dependence upon output device characteristics of an image information output device, into which the image information is to be fed, are carried out. The image information filing methods in an image processing system in accordance with the present invention is characterized by appending profile information for each processing to the image information in a step prior to one of the afore said processings, the profile information being necessary for each of the subsequent processings.
In a first filing method in accordance with the present invention, the filing (i.e., the appending) is carried out in a step prior to the processing for canceling the dependence upon input device characteristics. In a second filing method in accordance with the present invention, the filing is carried out in a step prior to the normalization processing. In a third filing method in accordance with the present invention, the filing is carried out in a step prior to the image processing. In a fourth filing method in accordance with the present invention, the filing is carried out in a step prior to the processing for canceling the dependence upon output device characteristics.
Specifically, the present invention also provides a first image information filing method in an image processing system; to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected, the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means, and
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image in formation, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously,
the image information filing method comprising:
appending pieces of profile information to the image information, which is fed into the input standardization means, the pieces of profile information comprising first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means, second profile information, which is necessary for defining details of the image processing carried out by the image processing means, third profile information, which is necessary for defining details of the normalization processing carried out by the normalization processing means, and fourth profile information, which is necessary for defining details of the transform processing carried out by the input standardization means.
The present invention further provides a second image information filing method in an image processing system, to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected, the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into input standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the input standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means, and
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously,
the image information filing method comprising:
appending pieces of profile information to the input standard image information, the pieces of profile information comprising first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means, second profile information, which is necessary for defining details of the image processing carried out by the image processing means, and third profile information, which is necessary for defining details of the normalization processing carried out by the normalization processing means.
The present invention still further provides a third image information filing method in an image processing system, to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected, the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into input standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the input standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means, and
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously,
the image information filing method comprising:
appending pieces of profile information to the image information which has been normalized, the pieces of profile information comprising first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means, and second profile information, which is necessary for defining details of the image processing carried out by the image processing means.
The present invention also provides a fourth image information filing method in an image processing system, to which at least one image information input apparatus having inherent input device characteristics and at least one image information output device having inherent output device characteristics are connected, the image processing system comprising:
i) an input standardization means for carrying out transform processing on image information, the transform processing being carried out such that, in every case where the image information has been received from one image information input apparatus, which is among connected image information input apparatuses, the received image information may be transformed into input standard image information, which does not depend upon the input device characteristics of the one image information input apparatus having fed the image information and depends upon standard device characteristics having been set previously,
ii) a normalization processing means for carrying out normalization processing for normalizing and extracting image information, which is contained in the input standard image information and corresponds to a desired image portion,
iii) an image processing means for carrying out desired image processing on the image information, which has been normalized by the normalization processing means, and
iv) an output standardization means for carrying out transform processing on the image information, which has been obtained from the image processing, the transform processing being carried out such that, in every case where the image information, which has been obtained from the image processing, is to be fed into and reproduced as a visible image by one image information output device, which is among connected image information output devices, the image may be reproduced by the one image information output device to be fed with the image information and as an image, which does not depend upon the output device characteristics of the one image information output device to be fed with the image information and depends upon standard device characteristics having been set previously,
the image information filing method comprising:
appending profile information to the image information, which has been obtained from the image processing, the profile information being first profile information, which is necessary for defining details of the transform processing carried out by the output standardization means.
The present invention further provides an image output device, comprising:
i) an image output means for reproducing a visible image from image information, which has been subjected to image processing carried out by assuming output gradation and is provided with subsidiary information representing the assumed output gradation, and
ii) a gradation correcting means for correcting the gradation of the image information in accordance with the subsidiary information and output gradation characteristics of the image output means, the correction being made such that the gradation of the output image reproduced by the image output means may approximately coincide with the assumed output gradation.
In the image output device in accordance with the present invention, the gradation correcting means may be provided with a look-up table forming means for forming a gradation correction look-up table such that the gradation of the output image reproduced by the image output means may approximately coincide with the assumed output gradation, and
the gradation correcting means may transform the gradation of the image information in accordance with the formed gradation correction look-up table.
Alternatively, the gradation correcting means may comprise:
a plurality of gradation correction look-up tables having different correction characteristics for correcting the gradation of the image information, and
a selection means for selecting a gradation correction look-up table, which is among the plurality of the gradation correction look-up tables and has the correction characteristics such that the gradation of the output image reproduced by the image output means may become closest to the assumed output gradation.
In the image output device in accordance with the present invention, the subsidiary information is the information, which is outputted (or inputted) by being appended to the image information. The subsidiary information may take on any form, which can define the output gradation assumed at the time of the image processing. For example, the subsidiary information may be given as lattice point data of a look-up table (LUT) or as numerical information representing a xcex3 value, which defines the gradation characteristics.
With the first image processing system in accordance with the present invention, the standardization means cancels the dependence of the received image information upon the input device characteristics, and carries out the transform processing such that the received image information may be transformed into the image information, which depends upon the standard characteristics having been set previously for each image input modality. Therefore, in every case where the image information has been received from one image information input apparatus, within the range of the same kind of image input modality, the same image processing can be carried out on the image information without a difference in image information input apparatus having fed the image information being taken into consideration. In this manner, approximately identical effects of the image processing can be obtained. Also, in cases where the image information having been obtained from the standardization means is fed into a single image information output device, an image with image quality giving an approximately identical impression can be obtained.
Accordingly, the person, who views the image, can view the image information, which has been obtained from each image information input apparatus, as an image having unified image quality without considering what manufacturer produced the image information input apparatus having fed the image information and without considering a difference in type or version between the image information input apparatuses in cases where they are of the same manufacturer. As a result, in particular, the efficiency and accuracy of diagnosis of an illness can be enhanced.
With the second image processing system in accordance with the present invention, the standardization means cancels the dependence of the received image information upon the input device characteristics, and carries out the transform processing such that the received image information may be transformed into the image information, which depends upon the standard characteristics of the system that have been set previously. Therefore, in every case where the image information has been received from one image information input apparatus, the same image processing can be carried out on the image information without a difference in image information input apparatus having fed the image information and a difference in image input modality being taken into consideration. In this manner, approximately identical effects of the image processing can be obtained. Also, in cases where the image information having been obtained from the standardization means is fed into a single image information output device, an image with image quality giving an approximately identical impression can be obtained.
Accordingly, the person, who views the image, can view the image information, which has been obtained from each image information input apparatus, as an image, which has image quality conforming to a unified criterion, without considering what manufacturer produced the image information input apparatus having fed the image information and without considering whether the image input modality is or is not the same. As a result, with diverse viewing, in particular, the efficiency and accuracy of diagnosis of an illness can be enhanced.
With the third image processing system in accordance with the present invention, before the image information is fed into one of the image information output devices having inherent output device characteristics, the standardization means carries out the processing for canceling the output device characteristics of the image information output device to be fed with the image information. Also, the standardization means carries out the transform processing on the image information such that the image information may be transformed into the image information, which depends upon the standard characteristics having been set previously for each kind of the image information output device. Therefore, in every case where the image information (the image) is to be reproduced by one image information output device, within the range of the same kind of image information output device, an image having identical image quality can be reproduced by the image information output device to be fed with the image information.
Accordingly, the same image processing can be carried out on the image information without a difference in image information output device to be fed with the image information being taken into consideration. In this manner, approximately identical effects of the image processing can be obtained. Also, the person, who views the image, can view the image, which is reproduced by each image information output device, as an image, which has image quality conforming to a unified criterion, without considering what manufacturer produced the image information output device to be fed with the image information and without considering a difference in type or version between the image information output devices in cases where they are of the same manufacturer. As a result, in particular, the efficiency and accuracy of diagnosis of an illness can be enhanced.
With the fourth image processing system in accordance with the present invention, before the image information is fed into one image information output device, the standardization means cancels the output device characteristics of the image information output device to be fed with the image information. Also, the standardization means carries out the transform processing on the image information such that the image information may be transformed into the image information, which depends upon the standard characteristics of the system that have been set previously. Therefore, in every case where the image information (the image) is to be reproduced by one image information output device, the same image processing can be carried out on the image information without a difference in image information output device to be fed with the image information and a difference in kind of the image information output device being taken into consideration. In this manner, approximately identical effects of the image processing can be obtained, and an image with image quality giving an approximately identical impression can be obtained.
Accordingly, the person, who views the image, can obtain an image, which has image quality conforming to a unified criterion, from each image information output device without considering what manufacturer produced the image information output device to be fed with the image information and without considering whether the kind of the image information output device is or is not the same. As a result, with diverse viewing, in particular, the efficiency and accuracy of diagnosis of an illness can be enhanced.
With the fifth image processing system in accordance with the present invention, with respect to the image information, which has been received from one of image information input apparatuses having inherent input device characteristics and is to be fed into one of the image information output devices having inherent output device characteristics, before the image information is fed into the one image information output device, the standardization means carries out the processing for canceling the input device characteristics of the image information input apparatus having fed the image information and the output device characteristics of the image information output device to be fed with the image information. Also, the standardization means carries out the transform processing on the image information such that the image information may be transformed into the image information, which depends upon the standard characteristics of the system that have been set previously for each combination of the kind of the image input modality and the kind of the image information output device. Therefore, in every case where the image information has been received from one image input modality and is to be reproduced as an image by one image information output device, within the range of the same combination of the kind of the image input modality and the kind of the image information output device, an image having image quality conforming to a unified criterion can be reproduced by the image information output device to be fed with the image information.
Accordingly, the same image processing can be carried out on the image information without a difference in image information input apparatus having fed the image information and a difference in image information output device to be fed with the image information being taken into consideration. In this manner, approximately identical effects of the image processing can be obtained. Also, the person, who views the image, can view the image, which is reproduced by each image information output device, as an image, which has image quality conforming to a unified criterion, without considering a difference in manufacturer, type, or version of the image information input apparatus having fed the image information and a difference in manufacturer, type, or version of the image information output device to be fed with the image information. As a result, in particular, the efficiency and accuracy of diagnosis of an illness can be enhanced.
With the sixth image processing system in accordance with the present invention, with respect to the image information, which has been received from one of image information input apparatuses having inherent input device characteristics and is to be fed into one of the image information output devices having inherent output device characteristics, before the image information is fed into the one image information output device, the standardization means carries out the processing for canceling the input device characteristics of the image information input apparatus having fed the image information and the output device characteristics of the image information output device to be fed with the image information. Also, the standardization means carries out the transform processing on the image information such that the image information may be transformed into the image information, which depends upon the standard characteristics of the system that have been set uniformly regardless of the combination of the kind of the image input modality and the kind of the image information output device. Therefore, in every case where the image information has been received from one image input modality and is to be reproduced as an image by one image information output device, regardless of the combination of the kind of the image input modality and the kind of the image information output device, an image having image quality conforming to a unified criterion can be reproduced by the image information output device to be fed with the image information.
Accordingly, the same image processing can be carried out on the image information without a difference in image information input apparatus having fed the image information and a difference in image information output device to be fed with the image information being taken into consideration. In this manner, approximately identical effects of the image processing can be obtained. Also, the person, who views the image, can view the image, which is reproduced by each image information output device, as an image, which has image quality conforming to a unified criterion, without considering a difference in kind of image input modality, manufacturer, type, or version of the image information input apparatus having fed the image information and a difference in kind, manufacturer, type, or version of the image information output device to be fed with the image information. As a result, in particular, the efficiency and accuracy of diagnosis of an illness can be enhanced.
With the seventh image processing system in accordance with the present invention, the response characteristics variation calculating means calculates variation in response characteristics, which occurs due to the image size enlargement or reduction processing, in accordance with the details of the image size enlargement or reduction processing. Also, the correction means carries out the frequency emphasis processing (including the smoothing processing) on the image information and in accordance with the variation in response characteristics. Therefore, an image, which has been compensated for the variation in response characteristics due to the image size enlargement or reduction processing, can be reproduced by the image information output device.
With the eighth image processing system in accordance with the present invention, the response characteristics variation calculating means calculates variation in response characteristics, which occurs due to the image size enlargement or reduction processing, in accordance with the details of the image size enlargement or reduction processing. Also, the correction means corrects the processing parameters (including those with the filter factors, or the like) for the transform processing, which is carried out on the image information by the standardization-means, in accordance with the variation in response characteristics. Therefore, an image, which has been compensated for the variation in response characteristics due to the image size enlargement or reduction processing, can be reproduced by the image information output device.
With the ninth image processing system in accordance with the present invention, the response characteristics variation calculating means calculates variation in response characteristics, which occurs due to the image size enlargement or reduction processing, in accordance with the details of the image size enlargement or reduction processing. Also, the correction means corrects the parameters (including those with the filter factors, or the like.), which are utilized for the interpolation processing accompanying the image size enlargement or reduction processing carried out on the image information, in accordance with the variation in response characteristics. Therefore, an image, which has been compensated for the variation in response characteristics due to the image size enlargement or reduction processing, can be reproduced by the image information output device.
Also, with each of the seventh, eighth, and ninth image processing systems in accordance with the present invention, the standardization means carries out the transform processing on the image information, such that the image information may be reproduced by one image information output device to be fed with the image information and as a visible image, which does not depend upon the response characteristics of the one image information output device to be fed with the image information and depends upon the standard characteristics having been set uniformly for the system. Therefore, the image quality of the reproduced image can be determined uniformly. Accordingly, in particular, the efficiency and accuracy of diagnosis of an illness can be prevented from becoming low due to the occurrence of a difference in image quality between reproduced images.
With the tenth, eleventh, twelfth, and thirteenth image processing systems and the first, second, third, and fourth image information filing methods in an image processing system in accordance with the present invention, in the image processing system wherein, with respect to the image information having been received from an image information input apparatus, the processing for canceling the dependence upon the input device characteristics of the image information input apparatus, the normalization processing, the image processing, and the processing for canceling the dependence upon the output device characteristics of an image information output device, into which the image information is to be fed, are carried out, the profile information, which is necessary for each of subsequent processings, is appended to the image information in a step prior to one of the aforesaid processings. Therefore, in a subsequent processing means or a subsequent processing step, the profile information appended to the image information can be read, and the details of the processing to be carried out can be determined from the profile information.
With the image output device in accordance with the present invention, the gradation of the image information is corrected in accordance with the gradation information, which represents the output gradation assumed at the time of image processing, and the output gradation characteristics of the image output means, which constitutes the image output device. The correction is made such that the gradation of the output image, which is ultimately reproduced by the image output device, may approximately coincide with the output gradation, which was intended at the time of the image processing. Therefore, regardless of the inherent gradation characteristics of the image output device, the gradation, which was intended at the time of the image processing, can be obtained. Specifically, in cases where the assumed output gradation varies for different images, an appropriate correction of gradation can be made with respect to each image, and therefore each image can be reproduced with the assumed output gradation.